Triple-expansion engine.



No. 719,367. 4 PATBNTBD JAN. 27, 1903.-

P. M. PRNSGOTT.

TRIPLE EXPANSION ENGINE.

APPLICATION FILED 00T.16, 1902.

Nirn STATES TRIPLE-EXPANSION ENGINE.

SPECIFICATION forming part of Letters Patent No. 719,367, dated. January 27, 1903. Y Original application iiled February 14, 1898J Serial No. 670,225. Divided and this application tiled October 16, 1902. Serial llo-1271583.

(No model.)

To @ZZ whom t rmty concern:

Be it known that I, FREDERICK M. PRES- COTT, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and usefulImprovementsinTriple-Expansion Engines, of which the following is a specification, reference being had to the accompanying drawing, forming a part thereof.

This invention relates to triple-expansion engines in which the cylinders are arranged in tandem end to end.

The main object of the invention is to facilitate access to and removal of the pistons and piston-rods without detaching or removing either of the several cylinders.

It consists in certain novel features in the construction and arrangement of component parts of the engine, as hereinafter particularly described, and pointed out in the claim.

The accompanying drawing is an axial section of a triple-expansion tandem engine embodying the invention.

A, B, and C designate, respectively, the high, intermediate, and low pressure cylinders arranged end to end in line with each other, and c, b, and c are the pistons fitted in said cylinders.

The high-pressure cylinder A is placed in front or next to the cross-head D, to which the several piston-rods are attached at their front ends, and the low-pressure cylinder C lsplaced at the rear or farthest from the crossead.

The high-pressure piston a is connected directly and centrally with the cross-head D by a single rod CZ, which passes through a stuffing-box in the front head E of cylinder A, and the intermediate piston b is directly and centrally connected with the piston a, by a rod passing through a sleeve or bushing g in the intervening cylinder-heads. The rod f may be formed integrally with or separate from the rod CZ, of which it constitutes an extension. It is preferably made integral with and larger than the rod d, so as to form a shoulder, against which the piston a is secured by a nuth, accessible through the front end of the cylinder A by the removal of its head e. The piston h is secured to the rear reduced end of the rod or extension f by a nut c, which is accessible through the rear end of cylinder B, as hereinafter explained.

The rear head j of the low-pressure cylinder C is detachable and removable, so as to permit the withdrawal of the piston c from said cylinder.

The intermediate andlow pressure cylinders B and C are vplaced close together and have a single removable head k between them to permit the withdrawal of the piston'b and the rods CZ and f through the low-pressure cylinder c. The annular space between the intermediate cylinder B and the low-pressure cylinder C around the head k is closed by a ring or ange Z, which may be cast, as shown, with the cylinder B.

The low-pressure piston C is connected with the cross-head D by side rods m m, passing through stuffing-boxes in the ring or Iiange Z exterior to the cylinders A and B, said piston being detachably secured to said rods by nuts 'n n or other suitable means accessible through the rear end of cylinder C.

From the foregoing description, in connection with the drawing, it will be obvious that access may be had to any of the several cylinders and any of the several pistons and piston-rods may be withdrawn therefrom by detaching and removing the cylinder-heads c, j, and 7s without detaching or displacing the cylinders.

I claim- In a triple-expansion engine the combination of high, intermediate and low pressure cylinders arranged in tandem end to end, and each provided with a removable head, pistons itted in the several cylinders, a single piston-rod centrally connecting the intermediate and high pressure pistons, a cross-head to which the front end of said rod is attached, and two piston-rods connecting the low-pressure piston with said cross-head exterior to the intermediate and low pressure cylinders, the intermediate and low pressure cylinders being close together and having a single removable head between them, substantially as described.

In witness whereof I hereto afx mysignature in presence of two witnesses.

FREDERICK M. PRESCOTT.

Witnesses:

CHAs. L. Goss, JOSEPH F. KAMINSKY. 

